The present invention relates to an electric hand power grinder, in particular an eccentric grinder, and also to abrasive carrier of a soft material for use on a grinding disk of the electric hand power grinder.
In a known eccentric grinder disclosed in U.S. Pat. No. 5,018,314 the abrasive carrier includes a rubber body mounted on a grinding plate and a grinding sheet which contains the abrasive and is alternatingly fixable as a wear part on the lower side of the rubber body. The rubber body is clamped over the outer edge of the grinding plate with a ring groove, which is formed on a bottom of a central opening of the outer thread of the rubber body which faces away from the grinding sheet. In another known vibration grinder disclosed in German document DE 197 08 086 the abrasive carrier which is called there a grinding plate is plate-shaped and mounted by screws on its vibration plate. The abrasive carrier includes a rigid upper plate and a lower plate of a soft material, as well as a grinding-grain containing grinding sheet which is releasably fixed by a flat adhesive connection to the lower plate.
Accordingly, it is an object of the present invention to provide an electric hand power grinder and an abrasive carrier which have the advantage of making available a grinding tool formed as a wear part which is price favorable and exchangeable fast without an auxiliary tool, so that it can be fast mounted on the grinding plate as well as released, and also optimal grinding results can be provided in different configurations.
A significant extension of the abrasive carrier over the grinding plate of the electric hand power grinder is prevented, so that when it is used up the hard griding plate does not abut against the tool.
When the electric hand power grinder is provided with a grinding dust aspiration, then in accordance with a preferable embodiment of the present invention the grinding plate and the abrasive carrier have congruent openings for aspiration of dust, and at the lower side of the grinding plate ring webs are formed which surround the suction openings of the grinding disk and axially project from it so as to form-lockingly engage into the dust suction openings of the abrasive carrier. With this structural design, the abrasive carrier is very accurately centered on the grinding disc, which contributes to reduction of vibrations in the machine housing.
In accordance with the preferable embodiment of the invention, the abrasive carrier has a support layer which is covered with a counter surface layer, and a grinding sheet which is held on the grinding element and is releasable from the support layer. Therefore between the support layer and the spraying disk, flat adhesive connection is provided whose pealing strength is smaller than the pealing strength of the flat adhesive connection between the grinding disk and the abrasive carrier. In this manner, during the exchange of the used up grinding sheet, the support layer remains adherent to the grinding plate and is not pulled out with it.
Preferably, the flat adhesive element is formed on the grinding disk as a burdock-like structure, which provide a flat adhesive connection with the counter adhesive layer arranged on the abrasive carrier, such as preferably velours or felt, or vice versa.
In accordance with a preferable embodiment of the inventive abrasive carrier, the counter adhesive layer which produces a flat adhesive connection with the flat adhesive element on the grinding plate of the electric hand power grinder is colored, in correspondence with the softness or hardness of the material of the abrasive carrier in a different manner. For example, soft material can be recognized by a red counter adhesive layer, extra soft material can be recognized by a white counter adhesive layer, and a hard material can be recognized by a black counter adhesive layer.
In accordance with a preferable embodiment of the invention, the material of the abrasive carrier can be formed as a grinding grain containing element, and preferably can be formed as an open-pore, grinding grain containing wool or fabric.
In accordance with a preferable embodiment of the invention, in the abrasive carrier two preferably differently colored layers with different grain sizes of the layer material are provided. They can be connected with one another directly or through an intermediate layer of a supporting sheet, for example of moss rubber, unseparably with one another. Depending on the grain size required for the grinding process, the abrasive carrier can be placed on the grinding plate with one or the other layer. Therefore, the surface adhesive element on the grinding plate, despite the grain size of the abrasive carrier side produces a good surface adhesive connection, especially when the two layers of the abrasive carrier are formed as open-pore, grinding grain-containing wool or fabric, and the flat adhesive element is formed as a burdock-type region.
In accordance with a further advantageous embodiment of the invention, the abrasive carrier has a preferably colored, grinding grain containing layer, which is inseparably or separably mounted on a supporting layer which carries the counter adhesive layer. In a preferable embodiment, the grinding-grain containing layer is formed as an open-pore wool or fabric and the supporting layer is composed of moss rubber.
In accordance with an alternative embodiment of the present invention, a further adhesive surface connection is formed between the separable grinding-grain containing layer which is for example composed of a grinding sheet, and a supporting layer which is for example composed of moss rubber. The pealing strength of the further adhesive surface connection is smaller than the pealing strength of the flat adhesive connection between the supporting layer and the grinding layer. In this case the supporting layer can be coated at both sides with velour or with a burdock-type region.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.